The present invention relates to a display device, and particularly to a direct-view-type display device which can provide a satisfactory display image in a wide area.
A flat display apparatus represented by a liquid crystal display device has been utilized in various fields, making the most of the characteristics of lightweight, small thickness and low power consumption. In particular, the liquid crystal display device is mainly used in portable information equipment represented by a personal computer.
Such a liquid crystal display device uses an insulating substrate made of, for example, glass. However, due to restrictions on the substrate or the apparatus, it has been difficult to realize a large display region of 20 inches or more.
A technique for forming a large display area by adhering together a plurality of liquid crystal display panels is known from, for example, Jpn. Pat. Appln. KOKAI Publication No. 8-146455.
However, a large display screen formed by adhering display panels as described above has required improvement, since joints are visible.
Under the circumstances, a technique disclosed in, for example, Jpn. Pat. Appln. KOKAI Publication No. 5-188340 or 10-253920 is known.
Jpn. Pat. Appln. KOKAI Publication No. 5-188340 discloses a combination of a cylindrical rod lens array for forming an erect life-size image and a Fresnel lens to obtain a magnified image. However, as indicated in Jpn. Pat. Appln. KOKAI Publication No. 10-253920, lightweight and low cost cannot be realized. In addition, a sufficient magnification in a short optical path cannot be satisfied.
On the other hand, Jpn. Pat. Appln. KOKAI Publication No. 10-253920 discloses a technique for realizing a lightweight and inexpensive magnifying optical system by arranging a field lens at an inverted image position between a pair of image-forming lens arrays and an aperture stop between the lens arrays. In other words, superposition of images projected through the lenses between the lens arrays is controlled to a relatively small extent by means of the field lens and the aperture stop, thereby preventing discontinuity of images and realizing uniform display brightness.
However, in the techniques described above, since it is necessary to shield most part of light by the aperture stop, reduction of the brightness of the device as a whole cannot be avoided.
The present invention was made to cope with the technical problems described above. Accordingly, its object is to provide a compact display device which can realize a sufficiently magnified image and obtain high display brightness.
The present invention, made on the basis of the above problems, resides in a display device comprising: a display panel having a predetermined effective display region; a display screen having an image display region larger than the effective display region of the display panel; and a magnifying optical system arranged between the display panel and the display screen and including a first inverting optical system constituted by a first lens array in which a plurality of first lenses corresponding to the display panel are arrayed and a second inverting optical system constituted by a second lens array in which a plurality of second lenses corresponding to the first lenses are arrayed, the magnifying optical system constituting a plurality of channels for forming on the display screen a magnified erect image for a display image on the display panel through the corresponding first and second lenses, the magnifying optical system forming an image of an image point on each portion of the display panel on the display screen through at least three of the channels.
The present invention also resides in a display device comprising: a display panel having a predetermined effective display region; a display screen having an image display region larger than the effective display region of the display panel; a magnifying optical system arranged between the display panel and the display screen and including a first inverting optical system constituted by a first lens array, in which a plurality of first lenses corresponding to the display panel are arrayed on a main surface of a display panel side and a plurality of second lenses are arrayed on an opposing main surface, and a second inverting optical system constituted by a second lens array, in which a plurality of third lenses corresponding to the first lenses are arrayed on a main surface of a first lens array side and a plurality of fourth lenses are arrayed on an opposing main surface, the magnifying optical system constituting a plurality of channels for forming on the display screen a magnified erect image for a display image on the display panel through the corresponding first and second lenses; and deflecting means for deflecting optical axes of light emitted from the display panel in accordance with a magnification of the magnifying optical system, the first to fourth lenses being arranged along the optical axes deflected by the deflecting means.
Further, the present invention resides in a display device comprising: a display panel having a predetermined effective display region; a display screen having an image display region larger than the effective display region of the display panel; a magnifying imaging optical system arranged between the display panel and the display screen and including a first inverting optical system constituted by a first lens array in which a plurality of first lenses corresponding to the display panel are arrayed and a second inverting optical system in which a plurality of second lenses corresponding to the first lenses are arrayed, the magnifying imaging optical system constituting a plurality of channels for forming on the display screen a magnified erect image for a display image on the display panel through the corresponding first and second lenses; and deflecting means for deflecting optical axes of light emitted from the display panel in accordance with a magnification of the magnifying optical system, the first and second lenses being arranged along the optical axes deflected by the deflecting means.
Further, the present invention resides in a display device comprising: a display panel having a predetermined effective display region; a display screen having an image display region larger than the effective display region of the display panel; and a magnifying optical system arranged between the display panel and the display screen and including a first inverting optical system constituted by a first lens array in which a plurality of first lenses corresponding to the display panel are arrayed and a second inverting optical system constituted by a second lens array in which a plurality of second lenses corresponding to the first lenses are arrayed, the magnifying optical system constituting a plurality of channels for forming on the display screen a magnified erect image for a display image on the display panel through the corresponding first and second lenses, a positional relationship of the first and second lenses being set so that arbitrary points on the display panel superpose each other on the display screen through the plurality of channels.
The present invention will be described in detail based on concrete examples. However, the present invention is not limited to the following concrete examples.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.